Structure and piezoelectric properties of poly(vinylidene fluoride) studied by density functional theory

Wang, Zhiyin; Fan, Huiqing; Su, Kehe; Wen, Zhenhai

doi:10.1016/j.polymer.2006.09.016

Cited by 72 publications

(53 citation statements)

References 47 publications

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“…Barrier 2 (Barr2) indicates the amount of energy required to reach T p from TG p ; $4 kcal/mol for PVDF, 1 kcal/mol for P(VDFTrFE), and 4.9 kcal/mol for P(VDF-CTFE) (vide Table I). For the PVDF case, the order of the energy difference is in agreement with that reported elsewhere [19]. On the other hand, Barrier 1 (Barr1) indicates the amount of energy required to reach T p from TG a being around 3.93, 2.01, and 3.99 kcal/mol following the same order mentioned before.…”

Section: Resultssupporting

confidence: 89%

“…Figure 2 shows that the TG a , TG p , and T p are stable geometric conformations for all the materials, because all of them are situated at minimum positions within the PES. We shall bear in mind that the molecular energy computed in this simplified model is far away from that of the real crystal (formed by large domains); nevertheless, computing simulations are consistent with available experimental observations [19]. According to Figure 2, it is possible to observe that for all the materials, the TG phases are energetically more stable than the T p phase, and that the PVDF-PES profile shows a symmetric curve distribution, which is mostly because of the symmetric disposition of fluorine substituents.…”

Section: Resultssupporting

confidence: 55%

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DFT study of ferroelectric properties of the copolymers: Poly(vinylideneflouride‐trifluoroethylene) and poly(vinylidene fluoride‐chlorotrifluoroethylene)

Ortiz

Cuán

Badillo

et al. 2010

Int J of Quantum Chemistry

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A theoretical study of poly(vinylidene flouride-trifluoroethylene) and poly(vinylidene fluoride-chlorotrifluoroethylene, is presented. By density functional theory calculations, some of the properties of these materials have been obtained. Among such properties, the dipolar moment and the energies associated to the structural changes. The B3LYP functional and 6311þG(d,p) bases set were used with Gaussian program. Calculations associated to different conformations were carried out to get insight about the involved phase changes. The energetic, charges, and dipole moment were calculated. The conformations, namely, I ¼ T p , II ¼ TG a , and III ¼ TG p , where T means trans and G means gauche, for the two polymers aforementioned were compared with the poly(vinilydene fluoride) studies previously obtained.

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Section: Resultssupporting

confidence: 89%

Section: Resultssupporting

confidence: 55%

DFT study of ferroelectric properties of the copolymers: Poly(vinylideneflouride‐trifluoroethylene) and poly(vinylidene fluoride‐chlorotrifluoroethylene)

Ortiz

Cuán

Badillo

et al. 2010

Int J of Quantum Chemistry

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“…This indicated a possible transition from α to β phase upon poling. This observation supports the study of Wang et al 39 who indicated that a critical positive electric field is needed to induce the transition from α chain to β chain. XRD traces of the unpoled and poled samples showed similar characteristic peaks.…”

Section: Microstructural Studiessupporting

confidence: 92%

Structural and Optical Properties of Manganese‐Doped NanocrystallineZinc Oxide/Polyvinylidene Fluoride Flexible Composite Thin Films Deposited by the Sol–Gel Method

et al. 2016

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Mn-doped nanocrystalline ZnO (Mn x Zn 1-x O) was incorporated in the polyvinylidene fluoride thin film for obtaining the free-standing flexible film by the sol-gel technique. The effect of Mn-ZnO loading on the optical and microstructural properties of the Mn-ZnO/polyvinylidene fluoride (PVDF) composite films was studied critically for the as-deposited and the poled samples. X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy were carried out to study the bonding environment. The XPS spectra recorded for poled samples from the fluorine-terminated surface showed a very strong peak at ß695 eV for F1s arising due to C-F bonds. Raman studies showed the presence of the predominant β phase of PVDF in the sample. Peaks related to ZnO nanocrystals were also observed in the Raman spectra. Photoluminescence spectra indicated a strong emission band at ß2.79 eV in the ultraviolet region arising out of near band edge emission of free excitons. C

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“…Many comparative studies on the structure and piezoelectric properties of α-and β-PVDF crystals have been performed [12,13], and most current research focuses on enhancing the β-phase in PVDF in order to achieve good piezoelectric properties. Zhu et al [14] used molecular mechanics methods to study PVDF, and obtained a piezoelectric coefficient of -0.461 Å/V in β-PVDF crystals.…”

Section: Introductionmentioning

confidence: 99%

Simulation of α- and β-PVDF melting mechanisms

Erdtman

Satyanarayana

Bolton

2012

Polymer

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Molecular dynamics (MD) simulations have been used to study the melting of α-and β-poly (vinylidene fluoride) (α-and β-PVDF). It is seen that melting at the ends of the polymer chains precedes melting of the bulk crystal structure. Melting of α-PVDF initially occurs via transitions between the two gauche dihedral angles (G ↔ G') followed by transitions between trans and gauche dihedral angles (T ↔ G/G'). Melting of β-PVDF initially occurs via T → G/G' transitions and via transitions of complete β-(TTTT) to α-(TGTG') quartet. The melting point of β-PVDF is higher than that of α-PVDF, and the simulated melting points of both phases depend on the length of the polymer chains used in the simulations. Since melting starts at the chain ends, it is important to include these in the simulations, and simulations of infinitely long chains yield melting points far larger than the experimental values (at least for periodic cells of the size used in this work), especially for β-PVDF. The simulated heats of fusion are in agreement with available experimental data.

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Structure and piezoelectric properties of poly(vinylidene fluoride) studied by density functional theory

Cited by 72 publications

References 47 publications

DFT study of ferroelectric properties of the copolymers: Poly(vinylideneflouride‐trifluoroethylene) and poly(vinylidene fluoride‐chlorotrifluoroethylene)

DFT study of ferroelectric properties of the copolymers: Poly(vinylideneflouride‐trifluoroethylene) and poly(vinylidene fluoride‐chlorotrifluoroethylene)

Structural and Optical Properties of Manganese‐Doped NanocrystallineZinc Oxide/Polyvinylidene Fluoride Flexible Composite Thin Films Deposited by the Sol–Gel Method

Simulation of α- and β-PVDF melting mechanisms

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